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Created page with "Pre-treatment structures are most cost effective when they slow down incoming flows, collect sediment for easy clean out, and slowly release water to the bioretention facility mitigating erosion. Pretreatment structures/strategies can include curb cuts, Aggregates, proprietary devices like filters or hydrodynamic separators, vegetation, concrete sumps, membrane filters, overland flow sumps, etc. '''Construction Steps:''' *Installation of pre-treatment fea..."
Pre-treatment structures are most cost effective when they slow down incoming flows, collect sediment for easy clean out, and slowly release water to the bioretention facility mitigating erosion. [[Pretreatment]] structures/strategies can include [[curb cuts]], [[Aggregates]], proprietary devices like filters or hydrodynamic separators, vegetation, concrete sumps, membrane filters, overland flow sumps, etc.
'''Construction Steps:'''
*Installation of pre-treatment features will vary based upon type. Similarly, installation timeline will range with type and could occur at excavation and mass grading, curb work or at finishing grade. Given pre-treatment features are typically integrated with the LID inlet coordination amongst multiple sub-contractors is sometime needed. The following details steps for various pre-treatment types:
*Vegetation: Follow the guidance shown below in the section “Plant Material Verification and Installation”
*Curbing: Follow the guidance shown above in the section “Curbing”.
*Aggregate: Follow the guidance shown above in the section “Stone reservoir”.
<gallery mode="packed" widths=300px heights=300px>
IMG_0891.JPG|Aggregate material (rock) installed as the inlet and pre-treatment device in the rain garden at Glendale P.S. in Brampton, ON. The runoff comes from a vegetated swale into the inlet, conveying it into the rain garden.
IMG_0744.JPG|Aggregate material (rock) installed as the inlet and pre-treatment device in the rain garden at Glendale P.S. in Brampton, ON. The runoff comes from a vegetated swale into the inlet, conveying it into the rain garden.
IMG_0788-1.JPG|Aggregate material (rock) installed as the inlet and pre-treatment device in the rain garden at Glendale P.S. in Brampton, ON. The runoff comes from a vegetated swale into the inlet, conveying it into the rain garden.
</gallery>
[[Category:Gallery]]
*Proprietary pre-treatment device:
#Excavate and prepare base for proprietary pre-treatment device according to design.
#Install proprietary pre-treatment device according manufacturer directions.
#Manufacturer representative may need to confirm proper installation and functioning through approved testing and inspection. <br>
<gallery mode="packed" widths=275px heights=275px>
P1160102.JPG|Installation of Jellyfish filter and sorbtive media vault at the IMAX bioswale project in Mississauga, ON.
P1160117.JPG|Installation of Jellyfish filter and sorbtive media vault at the IMAX bioswale project in Mississauga, ON.
P1160121.JPG|Installation of Jellyfish filter and sorbtive media vault at the IMAX bioswale project in Mississauga, ON.
</gallery>
[[Category:Gallery]]
'''Key Inspection Points:'''
*Verify that the correct pre-treatment device (jellyfish filter, vegetation, curbing, etc.) is being installed.
*Verify that all components of the pre-treatment device are installed
*Verify correct size and location of pre-treatment device.
*Verify correct elevation, slope, and footing according to design
*Is it tied into the curb, downspout, or other inlet? Or could happen before the curbing?
*Wet weather performance check:
**Does it work?
**Is water entering the LID facility properly?
**Is sediment and debris accumulating?
**Is it dissipating erosive forces?
'''Mistakes to Avoid:'''
*Pre-treatment component parts are missing
*Grading/elevation errors that deviates from design
**Incorrect pipe inverts causing short circuiting
**Insufficient grade drop or slope into pre-treatment to ensure positive flow of water
**Improper grading from pre-treatment to LID feature inhibiting positive flow
**Insufficient sump depth to account for sediment and debris accumulation
*Using wrong concrete forms if concrete curbs are part of pre-treatment.
For more information about pre-treatment strategies and their design, visit these page: [[Pretreatment]] and [[Pretreatment features]].
'''Construction Steps:'''
*Installation of pre-treatment features will vary based upon type. Similarly, installation timeline will range with type and could occur at excavation and mass grading, curb work or at finishing grade. Given pre-treatment features are typically integrated with the LID inlet coordination amongst multiple sub-contractors is sometime needed. The following details steps for various pre-treatment types:
*Vegetation: Follow the guidance shown below in the section “Plant Material Verification and Installation”
*Curbing: Follow the guidance shown above in the section “Curbing”.
*Aggregate: Follow the guidance shown above in the section “Stone reservoir”.
<gallery mode="packed" widths=300px heights=300px>
IMG_0891.JPG|Aggregate material (rock) installed as the inlet and pre-treatment device in the rain garden at Glendale P.S. in Brampton, ON. The runoff comes from a vegetated swale into the inlet, conveying it into the rain garden.
IMG_0744.JPG|Aggregate material (rock) installed as the inlet and pre-treatment device in the rain garden at Glendale P.S. in Brampton, ON. The runoff comes from a vegetated swale into the inlet, conveying it into the rain garden.
IMG_0788-1.JPG|Aggregate material (rock) installed as the inlet and pre-treatment device in the rain garden at Glendale P.S. in Brampton, ON. The runoff comes from a vegetated swale into the inlet, conveying it into the rain garden.
</gallery>
[[Category:Gallery]]
*Proprietary pre-treatment device:
#Excavate and prepare base for proprietary pre-treatment device according to design.
#Install proprietary pre-treatment device according manufacturer directions.
#Manufacturer representative may need to confirm proper installation and functioning through approved testing and inspection. <br>
<gallery mode="packed" widths=275px heights=275px>
P1160102.JPG|Installation of Jellyfish filter and sorbtive media vault at the IMAX bioswale project in Mississauga, ON.
P1160117.JPG|Installation of Jellyfish filter and sorbtive media vault at the IMAX bioswale project in Mississauga, ON.
P1160121.JPG|Installation of Jellyfish filter and sorbtive media vault at the IMAX bioswale project in Mississauga, ON.
</gallery>
[[Category:Gallery]]
'''Key Inspection Points:'''
*Verify that the correct pre-treatment device (jellyfish filter, vegetation, curbing, etc.) is being installed.
*Verify that all components of the pre-treatment device are installed
*Verify correct size and location of pre-treatment device.
*Verify correct elevation, slope, and footing according to design
*Is it tied into the curb, downspout, or other inlet? Or could happen before the curbing?
*Wet weather performance check:
**Does it work?
**Is water entering the LID facility properly?
**Is sediment and debris accumulating?
**Is it dissipating erosive forces?
'''Mistakes to Avoid:'''
*Pre-treatment component parts are missing
*Grading/elevation errors that deviates from design
**Incorrect pipe inverts causing short circuiting
**Insufficient grade drop or slope into pre-treatment to ensure positive flow of water
**Improper grading from pre-treatment to LID feature inhibiting positive flow
**Insufficient sump depth to account for sediment and debris accumulation
*Using wrong concrete forms if concrete curbs are part of pre-treatment.
For more information about pre-treatment strategies and their design, visit these page: [[Pretreatment]] and [[Pretreatment features]].